Electical header assemblies are often used to make electrical connection to a circuit board. One example of a header assembly that was developed for use in the auto industry is disclosed in U.S. Pat. No. 4,491,376 and comprises a one-piece dielectric housing supporting a plurality of conductor pins. One end of the conductor pins projects out of the housing and is bent downwardly at an angle of approximately 90.degree. for electrical connection to the circuit board to which the header assembly is to be mounted. The circuit board is provided with a precise pattern of holes through which the bent ends of the conductor pins extend, and the pins are soldered or otherwise electrically connected to conductive paths on one or both sides of the board.
The opposite ends of the conductor pins are adapted to be mated with conductors in a connector member designed to be plugged into the header assembly housing to complete a plurality of electrical circuits through the connector member and header assembly.
It is often desirable to provide filtering of all or selected ones of the circuits connected through a header assembly, for example, to isolate those circuits from EMI or RFI interferences. For greatest convenience and flexibility, it is also desirable to incorporate the filtering structure within the header assembly; however, this has proven to be a problem due to limitations in size, available space, and packaging techniques.
Specifically, header assemblies, such as the one disclosed in U.S. Pat. No. 4,491,376, are frequently of fixed design to enable standardization; and any redesign of the header assembly to accommodate filtering structure must not change the positions of the conductor pins to an extent that would prevent the header assembly from being properly connected to a standardized printed circuit board or to a standardized connector member. Also, any redesign must not alter the general dimensions or configuration of the header assembly to a degree that would prevent it from fitting within the limiting space normally provided for it on the standardized circuit board.
In view of the difficulty of redesigning header assemblies to provide a filtering capability while maintaining standardization requirements, it has been the practice to incorporate the filtering structure on the printed circuit board. This is a less than satisfactory solution, however, as the filtering structure occupies valuable space on the printed circuit board which can often be put to better use and, in general, does not provide the flexibility that is desired.